Apparatus for suppressing false signals



c. E. GOINGS. APPARATUS FOR SUPPRESSING FA'LSE SiGNALS. APPLICATIONFILED MAR 22, l9l5.

1,335,3 30. Patented Main 30, 1920.

Mag;

v NITE STATES PATENT OFFICE.

CLARENCE E. GOINGS, or PHILADELPHIA, PENNSYLVANIA. ASsIGNoE, BY vIEsNEASSIGNMENTS, TO THE POSITION-LIGHT SIGNAL COMPANY, A coRPoRATIoN 0F Toall whom itmay concern:

Be it'known that I, CLARENCE GorNos,

a citizen of the United States of America, and a resident ofPhiladelphia, Pennsylvania, have invented certain new, and usefulImprovements in Apparatus for Suppressing False Signals, of which thefollowing is a specification. v

In the use of a light signal, for daylight indication, difliculties aremet with'due to the tendency of internal parts of the several unitsmaking up the signal to reflect back light falling on them in such a wayas-toshow an in fact the unit is not lighted. v

I refer, as an example of a daylight signal, towhat is known as theposition-light signals recently installed in the Pennsyl- Vania railroadnear Philadelphia, and in which. the indication is 'ven both for day andnight signaling by t e relative position of light-emissive surfaces,Each light'surface forms .part of a corresponding unit which comprises asourceof illumination, either in the form of a lamp '(or it might be inthe form of a reflect r serving to reflect the light from" a commonsource) a lens for concentrating and .directi'ngthe emergent beam, and acover glass to protect the lens, and by preference a reflector to con,centrate the rays and throw themout through the lens.

IVith units of this character a part of the light falling upon the coverglass from thefront thereof may, under some conditions, and especiallywhen the sun is near the opposite horizon, be reflected from the frontsurface thereof, and so illuminate it that it appears as if it wereilluminated by and from the source of light located in its rear.

Again, another part of such .light at such.

time may pass farther into the unit and, af-

ter being reflected and concentrated by in'-' ternal surfaces thereof,be reflectedback to likewise cause a false indication, standard signalsthe dificulties pointed out may to a great extent be avoided by the usof hoods which, by projecting forwardly over the cover glasses, shieldthe latter from the sun, but with dwarf signals the use of hoods isimpossible.

My invention has come the difliculties abovepointed out as due'toreflection, and while it is especially applicable todwarf-position-light signals, it

arentl li htedlun'it whereas I pp y g bered 850,817.

With

for its object to over- APPARATUSFOR SUPPBESSING- FALSE SIGNALS.

, is capable'of use in connection with standout may be presentin suchsignals.

The process and means employed by me for the purpose stated will bedescribed in connection with the accompanying drawing which is asectional view showing my 1I1V8I1- tion as ap lied to a signaling unitofa .position-lig t signal, as is shown in an application filed by'William Churchill and Alexander H. Rudd in the United States PatentOffice, 'July'13, I914, serially num- In this drawing, which illustratesone embodiment of the invention, 1 is a'suitable lens located inanopenin in the case 2. In the case behind the lens 1s a lamp 3, whilelocated above thelamp is a reflector 4. In front ofthe lens is aconcavo-convex cover glass 5, the cover glass and lens being held withinthe opening of the case by a mounting The face 7 of the casing ispreferably blackened to kill reflection therefrom and to afford abackground against which the illuminated unit may be seen,

In the accompanying drawings, the reflector is shown as above the lamp,and is adapted in connection with the lens used,

Specification '0': Letters Patent. Patented Mar. 30,1920.- Applicationfiled- March 2 2, 1915. Serial No. 16,176.

to reflect the rays diverging upwardly and located near the ground, andwhich is to be seen from above, the location of the reflector will bechanged, so that in connection with the lens used, the signal can beseen from above when near the signal.

I have found that by interposing between thelens and cover glass one ormore thickmesses of thin fabric 8, the reflections, which itis theobject of. this invention to overcome,

are either suppressed or reduced to such an extent as to beunobjectionable. I have found that black chiflon is suitable for thepurpose indicated, and that a unit, having the chiffon at the pointindicated, appears, even when viewed with a strong light fallingthereon, as not only .unilluminated, but as black, simulatingtheappearance of the blackened surface of the case,

Inasmuch as the fabric absorbs a certain portion of the light emanatingfrom the lamp 3 in signaling, care should be had to have the lamp ofsuflicient high candlepoWer to give illumination effective for thedesired signaling distance.

It will be noted that light passing through the ,coverglass from thefront and tending after passing therethrough to be reflected backthrough the cover glass by the interior faces of the unit, (such as ofthe lens of the lamp and of the reflector, all of which may serve ascondensing elements therefor), is when the fabric is employed, compelledto pass therethrough. The fabric either absorbs to a greater. or

I less extent these relatively feeble beams incident thereon, beforethey are concentrated by the 'refiecting and condensing faces in therear thereof, or else,,by diffusion, so alters the direction of theincident rays as to prevent the same being concentrated by thereflecting faces, to give the false indication. In either case, theincident beams are destroyed and broken up.

It will be noted that the llght absorbing medium which is permanentlylocated in front of the lens, does not cover such unit in the sense ofshutting off the beam produced by light originating within the unit, itsnature being such that it at the same time prevents the passage of suchlight While intercepting light falling thereon from the frontsufliciently to prevent reflections from the unit.

I am aware that it is old to'interpose in the path of a beam of light,issulng from a signaling lamp a colored roundel or a colored clothscreen for the purpose of giving a characteristic color indication tothe Sig: nal, but so far as I know such prior struc tures have notcontemplated or embodied the prevention of the giving false signalindication by incident light, as is herein described.

By the above illustration and description of a specific embodiment of.my invention, which is made in accordance with the requirements of thestatiites, I do not desire to be understood as limiting my inventionthereto, as the latter is susceptible of other embodiment, but whatI doclaim is,-';

1.'As a means of absorbing light falling upon and into a signal unit,having light-reflecting and condensing surfaces in its interior, a lightabsorbing medium located in front of such reflecting and condensingsurfaces, and intercepting'light on its passage thereto, but permittingthe passage of light of greater intensityoriginating in the unit.

upon and into a signal unit having light reflecting and condensingsurfaces in its 1n- 'terior, a light-absorbing, medium consisting of alayer of Woven fabriclocated in front.

2; As a means of absorbing light falling of such reflecting andcondensing surfacesv and intercepting light on its passage thereto, butpermitting the passageof light of greater intensity originating in theunit.

In testimony whereof I have hereunto signed my name in the presence oftwo wit-

